Deciding monotone duality and identifying frequent itemsets in quadratic logspace

  • Authors:
  • Georg Gottlob

  • Affiliations:
  • University of Oxford, Oxford, United Kingdom

  • Venue:
  • Proceedings of the 32nd symposium on Principles of database systems
  • Year:
  • 2013

Quantified Score

Hi-index 0.00

Visualization

Abstract

The monotone duality problem is defined as follows: Given two monotone formulas f and g in irredundant DNF, decide whether f and g are dual. This problem is the same as duality testing for hypergraphs, that is, checking whether a hypergraph H consists of precisely all minimal transversals of a hypergraph G. By exploiting a recent problem-decomposition method by Boros and Makino (ICALP 2009), we show that duality testing for hypergraphs, and thus for monotone DNFs, is feasible in DSPACE(log2 n), i.e., in quadratic logspace. As the monotone duality problem is equivalent to a number of problems in the areas of databases, data mining, and knowledge discovery, the results presented here yield new complexity results for those problems, too. For example, it follows from our results that whenever, for a Boolean-valued relation (whose attributes represent items), a number of maximal frequent itemsets and a number of minimal infrequent itemsets are known, then it can be decided in quadratic logspace whether there exist additional frequent or infrequent itemsets.